diff --git a/test/extensions.jl b/test/extensions.jl
index f7d7ab26b9..05a2a6bac6 100644
--- a/test/extensions.jl
+++ b/test/extensions.jl
@@ -98,9 +98,8 @@ using UUIDs
     isolate(loaded_depot=false) do
         mktempdir() do dir
             Pkg.Registry.add("General")
-            path = joinpath(@__DIR__, "test_packages", "TestWeakDepProject")
-            cp(path, joinpath(dir, "TestWeakDepProject"))
-            Pkg.activate(joinpath(dir, "TestWeakDepProject"))
+            path = copy_test_package(dir, "TestWeakDepProject")
+            Pkg.activate(path)
             Pkg.resolve()
             @test Pkg.dependencies()[UUID("2ab3a3ac-af41-5b50-aa03-7779005ae688")].version == v"0.3.26"
 
diff --git a/test/new.jl b/test/new.jl
index 7e0a51d82b..46f91168f7 100644
--- a/test/new.jl
+++ b/test/new.jl
@@ -3224,9 +3224,8 @@ end
 temp_pkg_dir() do project_path
     @testset "test entryfile entries" begin
         mktempdir() do dir
-            path = abspath(joinpath(dirname(pathof(Pkg)), "../test", "test_packages", "ProjectPath"))
-            cp(path, joinpath(dir, "ProjectPath"))
-            cd(joinpath(dir, "ProjectPath")) do
+            path = copy_test_package(dir, "ProjectPath")
+            cd(path) do
                 with_current_env() do
                     Pkg.resolve()
                     @test success(run(`$(Base.julia_cmd()) --startup-file=no --project -e 'using ProjectPath'`))
@@ -3238,9 +3237,8 @@ temp_pkg_dir() do project_path
 end
 @testset "test resolve with tree hash" begin
     mktempdir() do dir
-        path = abspath(joinpath(@__DIR__, "../test", "test_packages", "ResolveWithRev"))
-        cp(path, joinpath(dir, "ResolveWithRev"))
-        cd(joinpath(dir, "ResolveWithRev")) do
+        path = copy_test_package(dir, "ResolveWithRev")
+        cd(path) do
             with_current_env() do
                 @test !isfile("Manifest.toml")
                 @test !isdir(joinpath(DEPOT_PATH[1], "packages", "Example"))
diff --git a/test/project_manifest.jl b/test/project_manifest.jl
index ab6a6cc99f..41974ed612 100644
--- a/test/project_manifest.jl
+++ b/test/project_manifest.jl
@@ -7,9 +7,8 @@ using ..Utils
 temp_pkg_dir() do project_path
     @testset "test Project.toml manifest" begin
         mktempdir() do dir
-            path = abspath(joinpath(dirname(pathof(Pkg)), "../test", "test_packages", "monorepo"))
-            cp(path, joinpath(dir, "monorepo"))
-            cd(joinpath(dir, "monorepo")) do
+            path = copy_test_package(dir, "monorepo")
+            cd(path) do
                 with_current_env() do
                     Pkg.develop(path="packages/B")
                 end
@@ -60,4 +59,4 @@ temp_pkg_dir() do project_path
     end
 end
 
-end # module
\ No newline at end of file
+end # module
diff --git a/test/sources.jl b/test/sources.jl
index 1497464aab..e17c40d6c3 100644
--- a/test/sources.jl
+++ b/test/sources.jl
@@ -7,9 +7,8 @@ using ..Utils
 temp_pkg_dir() do project_path
     @testset "test Project.toml [sources]" begin
         mktempdir() do dir
-            path = abspath(joinpath(dirname(pathof(Pkg)), "../test", "test_packages", "WithSources"))
-            cp(path, joinpath(dir, "WithSources"))
-            cd(joinpath(dir, "WithSources")) do
+            path = copy_test_package(dir, "WithSources")
+            cd(path) do
                 with_current_env() do
                     Pkg.resolve()
                     @test !isempty(Pkg.project().sources["Example"])
diff --git a/test/utils.jl b/test/utils.jl
index ee19cb9bcb..7bbc606ade 100644
--- a/test/utils.jl
+++ b/test/utils.jl
@@ -270,9 +270,21 @@ function git_init_package(tmp, path)
     return pkgpath
 end
 
+function ensure_test_package_user_writable(dir)
+    for (root, _, files) in walkdir(dir)
+        chmod(root, filemode(root) | 0o200 | 0o100)
+
+        for file in files
+            filepath = joinpath(root, file)
+            chmod(filepath, filemode(filepath) | 0o200)
+        end
+    end
+end
+
 function copy_test_package(tmpdir::String, name::String; use_pkg=true)
     target = joinpath(tmpdir, name)
     cp(joinpath(@__DIR__, "test_packages", name), target)
+    ensure_test_package_user_writable(target)
     use_pkg || return target
 
     # The known Pkg UUID, and whatever UUID we're currently using for testing
diff --git a/test/workspaces.jl b/test/workspaces.jl
index acb41be7bd..33b75d2baa 100644
--- a/test/workspaces.jl
+++ b/test/workspaces.jl
@@ -148,9 +148,8 @@ end
 
 @testset "test resolve with tree hash" begin
     mktempdir() do dir
-        path = abspath(joinpath(@__DIR__, "../test", "test_packages", "WorkspaceTestInstantiate"))
-        cp(path, joinpath(dir, "WorkspaceTestInstantiate"))
-        cd(joinpath(dir, "WorkspaceTestInstantiate")) do
+        path = copy_test_package(dir, "WorkspaceTestInstantiate")
+        cd(path) do
             with_current_env() do
                 @test !isfile("Manifest.toml")
                 @test !isfile("test/Manifest.toml")